1. Field of the Invention
The present invention relates to an adjustable wrench, and more particularly to an adjustable wrench that has a preferred structural strength and can rotate bolts of different sizes conveniently.
2. Description of Related Art
A conventional adjustable wrench comprises a handle, a fixed jaw, a rotating shaft, and a movable jaw. The fixed jaw is formed on an end of the handle and has a curved inner side. The rotating shaft is rotatably mounted in the curved inner side of the fixed jaw to rotate in an opposite direction relative to the handle. The movable jaw is slidably mounted on the end of the handle, faces the fixed jaw and the rotating shaft to hold and rotate a hexangular head of a bolt in a backward or a forward direction. Although the conventional adjustable wrench can be used to rotate bolts of different sizes in the backward or the forward direction, the rotating direction of the rotating shaft is opposite to the rotating direction of the conventional adjustable wrench when the handle is rotated in a backward direction. Then, the conventional adjustable wrench cannot rotate backwardly with a smaller range of movement.
In addition, the movable jaw of the conventional adjustable wrench does not have a structure to block the hexangular head of the bolt. When the conventional adjustable wrench is used to rotate a small-size bolt, the engaging position between the hexangular head of the small-size bolt and the jaws of the conventional adjustable wrench is deeper than the engaging position between the hexangular head of the ordinary-size bolt and the jaws of the conventional adjustable wrench. When the conventional adjustable wrench is rotated, the corners of the hexangular head of the small-size bolt may be worn and torn by the jaws of the conventional adjustable wrench. Furthermore, when a hexangular head of a bolt is rotated by the conventional adjustable wrench, and the movable jaw abuts aslant against a flat of the hexangular head of the bolt. Because an inner side of the movable jaw is flat and the inner side of the movable jaw cannot securely abut against the flat of the hexangular head of the bolt when the movable jaw abuts aslant against the flat of the hexangular head of the bolt, this may reduce the torque of the conventional adjustable wrench and cannot prevent the hexangular head of the bolt escaping from the fixed jaw and the movable jaw. Then, the user cannot rotate the hexangular head of the bolt conveniently.
To overcome the shortcomings, the present invention provides an adjustable wrench to mitigate or obviate the aforementioned problems.